Inside Samsung Galaxy S 4's face and eye-tracking technology

Samsung on Thursday highlighted many new features in its latest Galaxy S 4 smartphone during a Broadway-style presentation, but was surprisingly quiet about the technology that tracks facial and eye movement, which could enhance the video and browsing experience on the device.

Samsung on Thursday highlighted many new features in its latest Galaxy S 4 smartphone during a Broadway-style presentation, but was surprisingly quiet about the technology that tracks facial and eye movement, which could enhance the video and browsing experience on the device.

The world's largest smartphone maker introduced its flagship Galaxy S 4 product with a 5-inch screen at an event in New York City. Among the gaggle of new features in the LTE smartphone is a function called Smart Display, in which a front-facing camera recognizes eye and face movement to pause a video or scroll down a browser without touching the screen.

The Smart Pause feature can pause a video if a user's face and eye moves away from the screen.

"It understands that you are looking at the phone, and when it sees you looking away, it will pause," said Drew Blackard, director of product planning at Samsung, during an interview at the Galaxy S4 launch event.

In a demonstration, a video paused when Blackard's eyes moved away from the screen and his face moved slightly toward the left. The video resumed when his face was looking at the screen.

The Smart Pause feature is only available for videos watched in the Samsung Video Player application, which includes titles from Samsung's Media Hub, which is an application that allows users to watch videos and TV shows. The Smart Pause feature can be activated or deactivated, Blackard said.

The Smart Pause feature won't work with video applications like YouTube, but the company is always evaluating opportunities and working with partners to bring new features, Blackard said.

Another related technology called Smart Scroll can scroll up or down a web page depending on a user's facial movement. A green indicator signals that the smartphone knows that the face is looking at the screen. Combined with the tilt of the smartphone, the browser windows will automatically scroll up or down.

Combined with facial recognition technology, tilting a browser is easier than moving the head up and down to scroll a web page, Blackard said, who demonstrated the feature.

"The reason why it's not my head up and down, it's because we've looked at that in the past and it's a jarring experience. Looking straight at the screen... is more natural," Blackard said.

The Smart Scroll also works to scroll emails, but not yet with applications like Polaris, which is an office productivity application for mobile devices.

The new technologies are part of a raft of new features introduced by Samsung so the smartphone could be used without touching the screen. The company has enabled gesture recognition technologies in which a hand can be hovered over the screen to preview news, email, files in a folder and information in calendars. Gestures can also be used to scroll in browser windows, switch between browser tabs, or even accept phone calls.

"We've done a lot of work in terms of discoverability and usability of these features," Blackard said.

The Galaxy S4 will be available from 327 operators in 155 countries starting at the end of April, though no specifics on its price or shipping were provided. The smartphone has a super AMOLED display with density of 441 pixels-per-inch, a 13-megapixel rear camera and a 2-megapixel front camera. It weighs 130 grams, is 7.9 millimeters thick and depending on the market, may come with a 1.9GHz quad-core processor or 1.6GHz Samsung Exynos 5 eight-core processor. Other features include up to 64GB of storage and 802.11ac Wi-Fi.